Optical reader comprising multiple color illumination

Abstract

An imaging module in one embodiment includes at least one multiple color emitting light source comprising a plurality of different colored LED dies each independently driveable so that the overall color emitted by the light source can be controlled and varied. The multiple color emitting light source can be controlled so that the color emitted by the light source is optimized for imaging or reading in a present application environment of the module. Further, the module can be configured so that control of the multiple color emitting light source automatically varies depending on a sensed condition, such a color present in a field of view of the module, the distance of the module to a target, and/or a predetermined criteria being met so that feedback is provided to a user. The module in a further aspect can include illumination light sources and aiming light sources which project light in different wavelength emission bands.

We claim:  
     
       1. An optical reader imaging module comprising: a first circuit board carrying a two dimensional image sensor; a second circuit board spaced forwardly of said first circuit board; a support assembly at least partially interposed between said firs circuit board and said second circuit board; an aiming system for projecting an aiming line comprising aiming LEDs, said aiming LEDs being mounted on said first circuit board; an illumination system for projecting a substantially uniform illumination pattern on a target area, said is illumination system comprising illumination LEDs mounted on said second circuit board; wherein said aiming LEDs are selected to emit light in a different visible color relative to a visible color emitted by said illumination LEDs so that said aiming pattern is in color contrast relative to said illumination pattern. 
     
     
       2. The imaging module of  claim 1 , wherein said aiming LEDs are selected to emit visible light in the green visible wavelength band, and wherein said illumination LEDs are selected to emit light in the red visible wavelength band. 
     
     
       3. The imaging module of  claim 1 , wherein said illumination LEDs are selected to emit white, light, and wherein said aiming LEDs are selected to emit light in a narrow visible color band of wavelengths within a white light wavelength band. 
     
     
       4. The imaging module of  claim 1 , wherein said aiming system and said illumination system comprise a common optical plate abutted against a front of said second circuit board. 
     
     
       5. The imaging module of  claim 1 , wherein said aiming system includes an aperture disposed forwardly relative to each of said plurality of LEDs, and imaging optics disposed optically forwardly relative to each aperture for projecting an aperture image into a target area. 
     
     
       6. The imaging module of  claim 1 , wherein said module includes a color filter disposed in said module, for preventing light in an emission color of said aiming light sources from reaching said two dimensional image sensor.